This disclosure generally relates to the measurement of electrical contact resistance. The term “contact resistance” refers to the contribution to the total resistance of a system which can be attributed to the contacting interfaces of electrical connections as opposed to intrinsic resistance. In particular, this disclosure relates to systems, apparatus, and methods for measuring electrical contact resistance at an interface of an electrically conductive coating and a cross-ply surface of a layer of carbon fiber-reinforced plastic (CFRP) material.
It is rather problematic to use the traditional two-contact resistance measurement in an aircraft environment to monitor and/or verify coating in joint holes because the second contact terminal must be a part of aircraft structure. This introduces a new resistance variable that is location dependent.